Context-Aware Collision Avoidance Devices and Collision Avoidance System Comprising the Same

ABSTRACT

Personnel and vehicle collision avoidance devices configured to be used in collision avoidance systems are disclosed. The collision avoidance devices are configured to be aware of the context (e.g. position, location, state, status, etc.) in which the person or vehicle is. This awareness allows the devices to avoid transmitting non-hazardous proximity warnings when the context does not warrant the transmission of proximity warnings, and to transmit special critical proximity warnings when the context warrants the transmission of such proximity warnings. To detect the context, the devices comprise one or more context-awareness mechanisms (e.g. user input interfaces, sensors, infra-red receivers, etc.), each of which being capable of detecting one or more particular contexts. A collision avoidance system comprising these personnel and vehicle collision avoidance devices is also presented.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application claims the benefits of priority of U.S.Provisional Patent Application No. 61/713,019, entitled “System andMethod for Reducing Non-Hazardous Proximity Warnings in CollisionAvoidance Systems”, and filed at the United States Patent and TrademarkOffice on Oct. 12, 2012; of U.S. Provisional Patent Application No.61/726,304, entitled “Proximity Warning System P.W.S. Use Cases”, andfiled at the United States Patent and Trademark Office on Nov. 14, 2012;and of U.S. Provisional Patent Application No. 61/767,409, entitled“Proximity Warning System”, and filed at the United States Patent andTrademark Office on Feb. 21, 2013, the content of all three documents isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to the field of safety devices,apparatuses and/or systems and more particularly to the field ofproximity warning and collision avoidance devices, apparatuses and/orsystems typically used in mining environments.

BACKGROUND OF THE INVENTION

Numerous underground mines are developed and are in operation throughoutthe world. Though safety measures are typically deployed to preventaccidents involving collisions between vehicles, machines, personneland/or obstacles in these mines, accidents unfortunately happen on aregular basis.

To minimize the risks of collisions, collision avoidance systems areincreasingly deployed. These systems come in various configurations anduse various technologies, all with their inherent advantages anddrawbacks.

One type of collision avoidance systems that is becoming popular inunderground mine environments involves the use of typically three typesof collision avoidance devices configured to be respectively mounted tovehicles, personnel, and obstacles. These devices are configured to formad hoc peer-to-peer wireless networks when they are within communicationrange of each other and can therefore transmit proximity warnings toeach other if proximity is detected from various sensors based onreceived signal strength, time-of-flight, radar, lasers or magneticfields.

However, even if these types of collision avoidance systems can providevaluable warnings to enhance safety at mine sites, it remains that thesesystems do not take into account the context in which the person or thevehicle carrying the device is before transmitting proximity warnings.Hence, these systems often cause the transmission of proximity warningseven though the context does not warrant it.

Non-limitative examples of non-hazardous proximity warnings include thenotification to a vehicle operator of personnel in the area whenpersonnel are passengers in the same or another vehicle, thenotification to a vehicle operator of personnel in the area whenpersonnel are in a refuge or other sheltered area, the notification to avehicle operator of vehicles in the area when the vehicles are parked ina garage, and the notification to personnel of a vehicle in the areawhen the vehicle is stopped or non-operating.

Unfortunately, current collision avoidance systems have a very limitedability to distinguish between non-hazardous situations, hazardoussituations, and very hazardous or critical situations, and thereforeoften issue proximity warnings in all these situations.

Understandably, the transmission of proximity warnings for non-hazardoussituations causes problems. For example, vehicle operators bombarded byundistinguished proximity warnings will be unable to distinguish betweenvery hazardous, hazardous and non-hazardous situations and will tend toignore most warnings, thereby causing preventable accidents.

Hence, in view of the foregoing, there is a need for an improvedcollision avoidance system, and related devices and methods,purpose-built for underground mines which will at least mitigate some ofthe shortcomings of systems using collision avoidance devices.

SUMMARY OF THE INVENTION

Some of the shortcomings of prior art collision avoidance systems usingvarious personnel, vehicle and obstacle devices are at least mitigatedby a collision avoidance system in which the personnel devices and thevehicle devices are configured to be aware of the particular context inwhich they are such as to control the transmission of proximitywarnings.

In accordance with the principles of the present invention, thepersonnel and vehicle devices are generally configured to detect thecontext (e.g. position, location, state, status, etc.) in which theperson or vehicle is such as to modulate the transmission of proximitywarnings based on the detected context.

In that sense, when the personnel or vehicle device detects that theperson or vehicle is in a non-hazardous situation which does not warrantthe transmission of a proximity warning, the device does not transmitproximity warnings. However, when the personnel or vehicle devicedetects that the person or vehicle is in a very hazardous or criticalsituation, the device transmits special critical proximity warnings toall vehicle operators in range, which triggers a special type ofnotification.

In some embodiments, the critical proximity warnings could be capable ofstopping every vehicles which receive the critical proximity warnings.However, in most underground mines, remotely stopping all vehicles inrange without the consent of the vehicle operators would be asignificant safety hazard since stopping the vehicle abruptly or in ahigh-risk area would often put the vehicle operator at risk. This is whyin typical embodiments, critical proximity warnings only trigger aspecial type of urgent notification.

The devices in accordance with the principles of the present inventionare generally used within collision avoidance systems comprising, inaddition to personnel devices worn by personnel and vehicle devicesmounted to vehicles and machinery, obstacle devices which are configuredto be mounted to obstacles and other fixed hazards.

The devices of such collision avoidance systems are typically able tocommunicate via an ad hoc peer-to-peer wireless network when they arewithin communication range of each other to minimize latency, or via awireless LAN, and to transmit proximity warnings depending of the typesof devices.

In the case of collision avoidance systems based on ad hoc peer-to-peernetworks, only certain connections are generally allowed between devicesin order, for instance, to accelerate ad hoc network forming. Forinstance, since another vehicle, an obstacle, and a person on foot canall be hazardous to a vehicle operator, vehicle devices can establishconnections with all three types of devices. However, since onlyvehicles are hazardous to personnel on foot, personnel devices can onlyestablish connections with vehicle devices. Understandably, since otherpersonnel and obstacles are typically not hazardous to personnel onfoot, personnel devices will not typically establish connections withother personnel devices and obstacle devices.

In the case of collision avoidance systems based on a wireless LAN,communications rely on an infrastructure network which must provideblanket coverage in the area(s) of interest. All connections areestablished via the infrastructure network (e.g. wireless LAN).

In typical yet non-limitative embodiments, the personnel and vehiclecollision avoidance devices generally comprise at least one buttypically several context awareness mechanisms (e.g. interfaces,sensors, systems, infra-red receivers, buttons, etc.) connected to acontrol module or processing unit (e.g. a central processing unit, amicrocontroller). These context awareness mechanisms monitor and collectvarious context-related data which are then transmitted to theprocessing unit for analysis.

The processing unit, using the received data and various decisionalgorithms, then determines whether the person or vehicle is in acontext (e.g. position, location, state, status, etc.) that does notwarrant the transmission of a proximity warning, or that warrants thetransmission of a critical proximity warning.

On the one hand, if the processing unit of the collision avoidancedevice determines that the person or vehicle is in a non-hazardoussituation, it will generally temporarily turn off or disable thetransmission of proximity warnings for as long as it is determined thatthe person or vehicle is in the non-hazardous situation.

On the other hand, if the processing unit of the collision avoidancedevice determines that the person or vehicle is in a very hazardoussituation, it will generally transmit a special type of proximitywarnings, i.e. critical proximity warnings. In typical thoughnon-limitative embodiments, these critical proximity warnings willtrigger a special type of urgent notification to vehicle operators inrange.

However, if the processing unit determines that the context is neithernon-hazardous nor critical, it will cause the transmission of a regularproximity warning.

In a first exemplary yet non-limitative implementation, the personneldevice will temporarily disable the transmission of proximity warningsif the person wearing the device is in a safe zone sheltered fromvehicle traffic (e.g. a lunch room, an electrical substation, etc.). Insuch implementation, the personnel device will comprise, as a contextawareness mechanism, a receiver, typically an infra-red receiverembedded in the personnel device, for detecting whether the person is inthe safe zone. This first implementation will typically prevent thetransmission of a proximity warning to an incoming vehicle since theperson wearing the device is in a non-hazardous location.

In a second exemplary yet non-limitative implementation, the personneldevice will temporarily disable the transmission of proximity warningswhile the person wearing the device is seated or in a seated position,since workers typically do not sit in the way of vehicle traffic. Insuch implementation, the device will comprise, as a context awarenessmechanism, a sensor, typically a pressure sensor located in the footwearof the person or in the seat of a vehicle, in communication with thepersonnel device, for transmitting pressure information indicative ofthe sitting or standing position of the person. This secondimplementation will typically prevent the transmission of a proximitywarning to a vehicle when the person wearing the device is actuallysitting in the vehicle or in a passing vehicle. Understandably, a personsitting in a vehicle poses no collision hazard to the vehicle he is inor to another incoming vehicle.

In a third exemplary yet non-limitative implementation, the vehicledevice will detect if the vehicle is parked, and therefore has itslights off, and increase the level of the transmitted proximity warningsto critical, to ensure that vehicle operators do not assume there is novehicle in close proximity because they cannot see any lights. In suchimplementation, the device will comprise, as a context awarenessmechanism, a sensor, typically an ignition on/off sensor, an oilpressure switch, an interface with the vehicle data bus or a movementdetector (e.g. a MEMS inertial sensor), in communication with thevehicle device, to determine if the vehicle is parked. This thirdimplementation will typically increase the level of proximity warningsto other vehicles and eliminate any proximity warning to personneldevices, if applicable.

In a fourth exemplary yet non-limitative implementation, the vehicledevice will temporarily disable the transmission of proximity warningsif the vehicle is in a safe zone sheltered from vehicle traffic (e.g. aparking, a garage, etc.). In such implementation, the device willcomprise, as a context awareness mechanism, a receiver, typically aninfra-red receiver, in communication with the vehicle device, fordetecting whether the vehicle is in the safe zone. This fourthimplementation will typically prevent the transmission of a proximitywarning to an incoming vehicle since the vehicle is parked in anon-hazardous location.

In a fifth exemplary yet non-limitative implementation, the personneldevice will temporarily disable the transmission of proximity warningsif the personnel device is in its charger. In such implementation, thedevice will comprise, as a context awareness mechanism, an electricalinterface to detect if it is in its charger. This fifth implementationwill typically prevent the transmission of a proximity warning to anincoming vehicle, since this means the personnel device is not worn by aperson.

Understandably, several other implementations are possible and variousimplementations could be combined. In that sense, personnel and vehicledevices in accordance with the principles of the present invention couldcomprise several context awareness mechanisms to allow a more precisedetermination of the location, position, state and/or status of theperson or vehicle.

By allowing the personnel and vehicle devices to detect the context inwhich the person or vehicle is, the personnel and vehicle devices areable to avoid the transmission of proximity warnings in non-hazardoussituations and to cause the transmission of critical proximity warningsin highly hazardous or critical situations. By reducing the transmissionof proximity warnings in non-hazardous situations and by augmenting theimportance of proximity warnings in highly hazardous or criticalsituations, the devices in accordance with the principles of the presentinvention generally prevent vehicle operators and personnel fromignoring warnings which could cause preventable accidents.

Other and further aspects and advantages of the present invention willbe obvious upon an understanding of the illustrative embodiments aboutto be described or will be indicated in the appended claims, and variousadvantages not referred to herein will occur to one skilled in the artupon employment of the invention in practice.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the inventionwill become more readily apparent from the following description,reference being made to the accompanying drawings in which:

FIG. 1 is an exemplary scenario involving a collision avoidance systemin accordance with the principles of the present invention.

FIG. 2 is a schematic diagram of an embodiment of a vehicle device inaccordance with the principles of the present invention.

FIG. 3 is a perspective view of an exemplary embodiment of a userinterface of the vehicle device in accordance with the principles of thepresent invention.

FIG. 4 is a schematic diagram of an embodiment of a personnel device inaccordance with the principles of the present invention.

FIG. 5 is a perspective view of an exemplary embodiment of a personneldevice in accordance with the principles of the present invention, thepersonnel device being integrated to a cap lamp.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Novel context-aware collision avoidance devices and a collisionavoidance system comprising the same will be described hereinafter.Although the invention is described in terms of specific illustrativeembodiments, it is to be understood that the embodiments describedherein are by way of example only and that the scope of the invention isnot intended to be limited thereby.

The context-aware collision avoidance devices in accordance with theprinciples of the present invention are generally deployed withincollision avoidance systems of the type comprising different types ofdevices configured to be respectively mounted to, or carried by, mobilevehicles and machinery, fixed hazards or obstacles, and personnel.

Typically, such collision avoidance systems comprise three types ofdevices, namely: 1) vehicle devices to be mounted to mobile vehicles andmachinery (collectively referred to as “vehicles”), 2) obstacle devicesto be mounted to obstacle and other fixed hazards (collectively referredto as “obstacles”), and 3) personnel devices to be carried by personnel(e.g. vehicle operators, workers, miners, etc.).

In operation, the various devices will communicate with each otherdirectly (e.g. through peer-to-peer network(s)) or indirectly (e.g.through communication network(s)). Once in communication, the variousdevices will be able to transmit proximity warnings to each other whenproximity is detected with the help of various methodologies (e.g.communication range, received signal strength, time of flight, radar,magnetic fields, laser-based location recognition, etc.).

In the present embodiment, the various devices communicate directly witheach other via peer-to-peer communication. Also, in the presentembodiment, proximity between devices is mainly detected by theradio-frequency communication range between various devices. In thatsense, in the present embodiment, the range of proximity detectionvaries from as low as 25 meters when devices are around corners with nodirect line-of-sight, to up to 100 meters when devices have a directline-of-sight.

Referring now to FIG. 1, an exemplary scenario of a collision avoidancesystem involving vehicles 10, obstacles 20 and personnel 30 isillustrated.

In the scenario of FIG. 1, which is located in an underground mine,there are several vehicles 10 equipped with vehicle devices 100, oneobstacle 20 provided with an obstacle device 200, and several workers 30equipped with personnel devices 300, all of them being in variouscontexts.

Starting with vehicle 10B, its vehicle device 100 establishespeer-to-peer connections with the devices of vehicle 10A, of obstacle20A, and of worker 30A, and receives proximity warnings from all ofthem. Consequently, the display 150B of the vehicle device 100 indicatesthe presence of vehicle 10A, obstacle 20A, and worker 30A, therebywarning the operator of their proximity.

Notably, as it will be best understood below, since the workers 30Bseated in the vehicle 10B all have their respective cap lamps 400 turnedoff, their respective personnel devices 300 do not establishpeer-to-peer connection with the vehicle device 100 of vehicle 10B.Hence, the vehicle device 100 of vehicle 10B does not receive proximitywarnings from the personnel devices 300 of workers 30B and does notcount them. Understandably, workers seated in a vehicle do not pose anycollision risks with the vehicle.

Also, though not shown in FIG. 1 for clarity purposes, the personneldevice 300 of worker 30A would also receive proximity warnings from thevehicle devices 100 of both vehicles 10A and 10B. Similarly, the vehicledevice 100 of vehicle 10A would receive proximity warnings from thevehicle device 100 of vehicle 10B, from the obstacle device 200 ofobstacle 20A, and from the personnel device 300 of worker 30A. However,for the same reason as the vehicle device 100 of vehicle 10B, thevehicle device 100 of vehicle 10A would not receive proximity warningsfrom the personnel devices of workers 30B because their cap lamps 400are turned off.

Notably, since the obstacle 20A would not pose a risk of collision tothe worker 30A, there would be no peer-to-peer communication between thedevices of obstacle 20A and of worker 30A.

Referring now to vehicle 10D, its vehicle device 100 establishespeer-to-peer connections with the vehicle device 100 of parked vehicle10E, which is located in a garage area, and with personnel device 300 ofworker 30G, and receives proximity warnings from them. Notably though,since vehicle 10E is parked, this status is specially indicated on thedisplay 150D of the vehicle device 100 of vehicle 10D (e.g. with aparked vehicle icon or identifier). Hence, the operator 30E of thevehicle 10D is being made aware of the presence of a vehicle 10 butsince the vehicle is parked, the risk of collision is significantlyhigher because the vehicle head lights are turned off and the vehicle istherefore harder to see in the ambient darkness of the underground mine.

Notably, the vehicle device 100 of vehicle 10D does not establishpeer-to-peer connections with the personnel devices 300 of workers 30Fsince they are located in the garage area with their cap lamp 400 turnedoff. In other words, since workers 30F do not pose any immediatecollision hazard to the vehicle 10D, they do not transmit proximitywarnings to the vehicle 10D.

Finally, referring to worker 30C, since he is afraid of being run overby vehicle 10C moving toward him, he triggers the transmission of acritical proximity warning to the vehicle device 100 of vehicle 10C. Insuch circumstances, the display 150C of the vehicle device 100 wouldwarn the operator 30D to stop immediately via a special notification.

In the embodiment of FIG. 1, peer-to-peer connections between personnelvehicle devices 100, obstacle devices 200 and personnel devices 300 areshown in dotted lines. Notably, as mentioned above, only the vehicledevices 100, obstacle devices 200 and personnel devices 300 which are incommunication range with another vehicle device 100, and vehicle devices100 which are in communication range with personnel devices 300 actuallyestablish a peer-to-peer connections. Devices which are not incommunication range do not establish peer-to-peer connections. In thepresent embodiment, the communication range of the devices generallycorrespond to the danger zone around the vehicle, obstacle or personnelin which proximity warning should be transmitted. In other embodiments,the danger zone or area around vehicle, obstacle and personnel could bedetermined via other mechanisms (e.g. received signal strength,time-of-flight, radar, lasers or magnetic fields, etc.).

In accordance with the principles of the present invention, the vehicledevice 100 and the personnel device 300 are each provided with contextawareness mechanisms which allows the vehicle device 100 and thepersonnel device 300 to temporarily disable the transmission ofproximity warnings when it is determined that the vehicle or the personis in a non-hazardous situation or context (e.g. location, position,state, status, etc.) that does not warrant the transmission of proximitywarnings, and to transmit critical proximity warnings when it isdetermined that the vehicle or the person is in highly hazardous orcritical situation or context (e.g. location, position, state, status,etc.) that warrants the transmission of the critical proximity warnings.

Vehicle Device

Referring to FIG. 2, an embodiment of a vehicle device 100 in accordancewith the principles of the present invention is illustrated.

The vehicle device 100 typically comprises a processing unit 110 (e.g. acentral processing unit, a microcontroller, a control module, etc.), atransceiver 120 connected to the processing unit 110 for communicatingwith other devices and for receiving and transmitting proximity warningsand other information via an omnidirectional antenna 130 connectedthereto, a memory unit 140 connected to the processing unit 110 forstoring programs, instructions, information and/or data relevant to theproper functioning of the device 100, a user interface 150 connected tothe processing unit 110, and at least one context awareness mechanism160.

In the present embodiment, as best shown in FIG. 3, the user interface150 typically comprises a display screen and one or more buttons, or atouch screen, and speaker(s) (e.g. buzzers) for notifying the operator30 of the vehicle 10 to which the vehicle device 100 is mounted.

In the present embodiment, the device 100 comprises two contextawareness mechanisms 160. One mechanism is configured to reducenon-hazardous proximity warnings, and the other mechanism is configuredto cause the transmission of critical proximity warnings.Understandably, in other embodiments, the context awareness mechanisms160 could comprise more or less than two different mechanisms and/orcould use mechanisms different from the ones about to be described. Inthat sense, various mine settings and configurations may warrant the useof additional and/or different mechanisms.

Reduction of Non-Hazardous Proximity Warnings

The context awareness mechanism to reduce the transmission of proximitywarnings is an infra-red receiver 162 mounted to the vehicle 10,typically on its top, and configured to detect coded IR signalstransmitted by IR transmitters properly deployed in the mine todelimitate safe zones such as garages, safe parking areas, etc.

When a vehicle 10 enters such a safe zone provided with an appropriateIR transmitter (not shown), the receiver 162 will pick up the coded IRsignals and forward the relevant information to the processing unit 110which will disable the transmission of proximity warnings to othervehicles and to personnel.

Hence, vehicles 10 and personnel 30 passing near such safe zones willnot receive proximity warnings from vehicle devices 100 of vehicles 10located in these safe zones as these vehicles 10 do not pose anycollision hazard to the vehicles 10 and personnel 30 in the mine.

In the present embodiment, to delimit the boundaries of a safe zone,which can end as abruptly as when a vehicle moves outside of a garageinto a tunnel with vehicle traffic, the use of IR signals is preferredover RF signals since well-defined demarcation lines can be created byconfining IR signal with simple optically opaque materials (e.g. plywoodboards, opaque polymeric curtains, etc.). RF signals tend to be morepervasive in nature and therefore more difficult to control orinterpret.

Transmission of Critical Proximity Warnings

The context-awareness mechanism 164 is a vehicle interface configured todetermine whether the vehicle 10 is parked. This mechanism 164 isconfigured to cause the processing unit 110 to transmit criticalproximity warnings to other vehicles 10 when the processing unit 110detects, via the vehicle interface 164, that the lights of the vehicle10 are turned off. Understandably, in an underground mine, a runningvehicle 10 always has its lights on. Hence, if the lights of the vehicle10 are turned off, it generally means that the vehicle is parked and notrunning. Understandably, the vehicle interface 164 could detect that thevehicle 10 is not running via other indicators (e.g. ignition switch,oil pressure, etc.).

Understandably, a vehicle 10 parked in a tunnel with its lights turnedoff could pose a very high risk of collision with an incoming vehicle10. Indeed, a vehicle with its lights turned off become a large yethard-to-see obstacle partially or completely blocking a tunnel.

Hence, when a vehicle device 100 receives such a critical proximitywarning, a special notification (e.g. a parked vehicle icon as inFIG. 1) is generally indicated on the display of the user interface 150.

Understandably, the processing unit 110 is generally configured tomanage conflicting information coming from the various context-awarenessmechanisms 160.

For instance, in the present embodiment of the vehicle device 100, ifthe vehicle 10 is parked in a safe parking area with its lights turnedoff, the processing unit 110 will receive conflicting information fromthe two context-awareness mechanisms 162 and 164. Indeed, the IRreceiver 162 will detect coded IR signals from the IR transmitterlocated in the safe parking area, indicating that no proximity warningsshould be sent, while the vehicle interface 164 will detect that thelights of the vehicle 10 are turned off, indicating that criticalproximity warnings should be sent.

In this case, the processing unit 110 would be configured such that thedetection of coded IR signals overrides the detection of turned offlights. Indeed, if the vehicle 10 is parked in a safe area, the device100 of such vehicle 10 should not send critical proximity warnings tonearby vehicles 10.

Understandably, depending on the actual context-awareness mechanisms 160used and on the contexts they are configured to determine, theprocessing unit 110 would be configured to perform conditional logicoperations and/or other operations to determine what is the primarydetected context upon which the decision to not transmit proximitywarnings, to transmit proximity warnings, or to transmit criticalproximity warnings should be based.

Personnel Device

Referring to FIG. 4, an embodiment of a personnel device 300 inaccordance with the principles of the present invention is illustrated.

The personnel device 300 typically comprises a processing unit 310 (e.g.a central processing unit, a microcontroller, a control module, etc.), atransceiver 320 connected to the processing unit 310 for communicatingwith other devices and for receiving and transmitting proximity warningsand other information via an omnidirectional antenna 330 connectedthereto, a memory unit 340 connected to the processing unit 310 forstoring programs, instructions, information and/or data relevant to theproper functioning of the device 300, a user interface 350 connected tothe processing unit 310, and at least one context awareness mechanism360.

In the present embodiment, the personnel device 300 is integrated intothe cap lamp 400 (see FIG. 5) for the following reasons:

-   -   a. Collision avoidance systems will actually increase the risk        of collisions if some of the workers 30 do not have personnel        devices 300 on them. Since nobody forgets their cap lamp when        going underground (without a cap lamp, one cannot see anything),        integration of the personnel device 300 with the cap lamp 400 is        the most reliable means of ensuring all workers have a personnel        device 300 on them.    -   b. Using the cap lamp OFF status as a means of determining if        the person is not at risk of collision, since the light is        always on in high-risk areas, whereas it is often turned off        when the person is operating a vehicle, is a passenger, or is in        a well-lit sheltered area like the lunch room, refuge or        electrical sub-station.    -   c. Using the cap lamp ON status as a necessary condition to        trigger a man-down alarm, as detected by an embedded motion        sensor, since workers will typically turn off their cap lamps        400 (via switch or button 410) when they take them off during a        break and leave them immobile on a hook or table.    -   d. Using the cap lamp 400 in charger as a means of determining        the device 300 is not worn by a person.    -   e. Using the cap lamp head light mounting location on the        helmet, to position the embedded infra-red receiver with a        line-of-sight view of any infrared transmitter used to flood a        safe zone with reference IR signals, whose propagation is        blocked by any opaque material, including clothes.    -   f. Ability to flash the head light, to notify the person of a        critical proximity warning, if required, since this is the most        reliable means of getting the person's attention    -   g. Quick access to emergency buttons in case of panic, since        buttons on cap lamp head light are always accessible and at the        exact same location, unlike a device mounted on the belt, a        necklace or in a pocket.    -   h. Ability to use cycling of power on cap lamp 400, an existing        interface familiar to personnel, to reset emergency stop alarms.

In the present embodiment, the context awareness mechanism 360 comprisessix different mechanisms.

The first four mechanisms are related to the reduction of non-hazardousproximity warnings. The other two mechanisms are related to thetransmission of critical proximity warnings. Understandably, in otherembodiments, the context awareness mechanism 360 could comprise more orless than six different mechanisms and/or could use mechanisms differentfrom the ones about to be described. In that sense, various minesettings and configurations may warrant the use of additional and/ordifferent mechanisms.

Reduction of Non-Hazardous Proximity Warnings

The first mechanism 361 to reduce the transmission of non-hazardousproximity warnings is an interface between the processing unit 300 andthe cap lamp controller (not shown). This mechanism 361 is configured todetect whether the cap lamp is turned on or off.

If the mechanism 361 detects that the cap light is turned off, themechanism 361 will transmit the information to the processing unit 310which, in turn, will disable the transmission of proximity warnings foras long at the cap lamp 400 is determined to be turned off.

Understandably, if the cap lamp 400 is turned off, it generally meansthat either the cap lamp 400 itself is not in use, or that the person 30wearing the cap lamp 400 is in a well-lit or safe area. In any of thesecases, the personnel device 300 should not transmit proximity warningsas no personnel is in a hazardous situation.

The second mechanism 362 for reducing non-hazardous proximity warningsis an infra-red (“IR”) receiver in communication with the processingunit 310.

In the present embodiment, the receiver 362 is mounted to, or integratedwith, the cap lamp 400 (see FIG. 5). This receiver 362 is configured toreceive coded IR signals from IR transmitters (not shown) properlydeployed in the mine to delimitate safe zones such as lunch areas,electrical substations, shelters, etc.

As a person 30 wearing his cap lamp 400 enters a safe zone, such as alunch area or an electrical substation, provided with an appropriate IRtransmitter (not shown), the receiver 362 will pick up the coded IRsignals and the processing unit 310 will disable the transmission ofproximity warnings.

Hence, vehicles 10 passing near such safe zones will not receiveproximity warnings from the personnel devices 300 of the persons 30located in these safe zones as these persons 30 do not pose anycollision hazard to the vehicles 10.

To define the boundaries of a safe zone, which can end as abruptly aswhen a person 30 takes a step outside of a refuge into the tunnel withvehicle traffic, the use of IR signals is preferred over RF signalssince well-defined demarcation lines can be created by confining IRsignals with simple optically opaque materials (e.g. plywood boards,opaque polymeric curtains, etc.). RF signals tend to be more pervasivein nature and therefore more difficult to control or interpret.

The third mechanism 363 to reduce the transmission of non-hazardousproximity warnings is a pressure sensor mounted in the footwear of theperson 30 carrying the device 300 and typically in wirelesscommunication with the processing unit 310.

The pressure sensor 363 measures the amount of pressure actually appliedthereon at regular intervals and transmits the collected data to theprocessing unit 310.

Upon receiving the pressure data, the processing unit 310 will comparethem to predetermined ranges and will determine whether the person 30carrying the device 300 is sitting or standing.

If the processing unit 310 determines that the person is sitting, thenthe processing unit 300 will disable the transmission of proximitywarnings for as long as the person is determined to be sitting.

Understandably, a person 30 that is sitting in the vicinity of a vehicleis likely to be the operator of the vehicle, a passenger in the vehicle,or the operator or a passenger of a nearby passing vehicle. In all thesesituations, the person will be in a vehicle and will therefore pose norisk of collision with another vehicle. In any event, personnel 30 inunderground mines never sit in areas where vehicles 10 travel.

Alternatively, to better control which sitting scenarios should turn offthe proximity warning signals, pressure sensors could be installed incushions placed at all the safe sitting areas and could be configured toestablish short-range wireless connection with the personnel device 300of the person 30 sitting on the cushion. Upon receiving pressure dataindicative of a person 30 sitting on the cushion, the processing unit310 of the device 300 would disable the transmission of proximitywarnings for as long as the person is sitting on the cushion.

The fourth mechanism is an interface 364 to detect if the cap lamp 400is in its charger (not shown), i.e. not currently worn by a person 30.

If the processing unit 310 receives data from the interface 364 that thecap lamp 400 is in its charger, then the processing unit 310 willdisable the transmission of proximity warnings since no one is actuallywearing the cap lamp 400 and thus the device 300. If no personnel 30 iswearing the device 300, then there is no danger of collision and thedevice 300 should not transmit proximity warnings.

Understandably, the personnel device 30 could comprise more or lessmechanisms 360 to reduce non-hazardous proximity warnings. Furthermore,some mechanisms 360 could work in cooperation to provide a more preciseindication of the context (e.g. position, location, state, status, etc.)in which the person 30 wearing the device 300 is.

Transmission of Critical Proximity Warnings

In the present embodiment, the first mechanism to trigger thetransmission of critical proximity warnings is an emergency interface365. In the present embodiment, as best shown in FIG. 5, the emergencyinterface 365 is two buttons disposed on both sides of the cap lamp 400and which cannot be pressed simultaneously by accident to avoid falsealarms. The position of the cap lamp 400 on the protective helmet allowsfor quick access of the two buttons of the emergency interface 365.

The emergency buttons 365 are in communication with the processing unit310 and are configured to transmit signals to the processing unit 310upon being simultaneously depressed.

When the processing unit 310 receives signals from the buttons 365, itcauses the transmission of a critical proximity warning to all thevehicles in communication range with the device 300 (see worker 30C andvehicle 10C in FIG. 1). This critical proximity warning will warn theoperator of the vehicle to stop immediately via the display of specialnotification (e.g. EMERGENCY STOP).

In other embodiments, this critical proximity warning could furthercause all the vehicles receiving the warning to stop automatically.

Though the emergency interface 365 is primarily designed to avoidimminent collisions, it could also be used in other situations where aworker 30 needs immediate assistance.

In embodiments where the devices 100, 200 and 300 are in communicationwith a wireless network (e.g. wireless LAN) deployed in the mine, thetransmission of a critical proximity warning could also be forwarded toa monitoring system for monitoring and analysis purposes.Understandably, a critical near-miss situation that required a person 30to initiate the transmission of a critical proximity warning should beanalyzed, when possible, to determine the cause of the near-misssituation and avoid such situations in the future.

The second mechanism to trigger the transmission of critical proximitywarnings is a movement detector 366 (e.g. inertial detector) connectedto the processing unit 310.

The movement detector 366 is configured to detect whether the person 30wearing the device 300 is actually moving.

In most situations, the person 30 wearing the cap lamp 400 always moves,even slightly. Hence, this second mechanism 366 is particularlyconfigured to detect whether a person lies unconscious because of aheart attack or heat stroke (generally referred to as a man-downsituation). In that sense, if a person is immobile for more than apredetermined amount of time (e.g. 3 minutes) and if the cap lamp light430 is turned on, the processing unit 310 will cause the transmission ofa critical proximity warning. Understandably, the predetermined amountof time could be more than 3 minutes or less than 3 minutes.

This critical proximity warning could be identical to the criticalproximity warning transmitted after the activation of the emergencyinterface 365, or it could be different. In that sense, the differencecould be in the message actually displayed on the interface 150 of thevehicle device 100. For instance, the display could indicate EMERGENCYSTOP—MAN-DOWN instead of only EMERGENCY STOP.

Notably, though personnel devices 300 are generally configured not totransmit proximity warnings to each other since personnel do not posecollision hazard to each other, in some embodiments, the personneldevice 300 could be configured to receive critical proximity warningstransmitted by a neighboring personnel device 300 in a man-downsituations. In such embodiments, when personnel device 300 transmits acritical proximity warning, every personnel 30 and vehicles 10 in thevicinity of that person 30 would be warned, at the very least forassistance purposes.

In the present embodiment, the user interface 350 of the personneldevice 300 typically comprises the cap lamp light 430 and could furthercomprise LED(s) 420, button(s), and/or buzzer(s) for notifying theperson 30 carrying the personnel device 300.

Still, in the present embodiment, since the device 300 is integrated tothe cap lamp 400, the processing unit 310 is in communication with thecap lamp controller such that the cap lamp controller could receiveinstructions from the processing unit 310 to modulate the cap lamp light430 (e.g. blink, flash, etc.) to warn the person 30 of the reception ofa proximity warning. For evacuation notification systems, this isgenerally recognized as the most reliable means of getting a person'sattention underground. The flashing pattern for critical proximitywarnings could be different from the flashing pattern of the evacuationnotification system, to enable both systems to get the person'sattention with the main cap lamp light 430.

Understandably, as for the processing unit 110 of the vehicle device100, the processing unit 310 of the personnel device 300 is generallyconfigured to manage conflicting information coming from the variouscontext-awareness mechanisms 360.

In that sense, depending on the actual context-awareness mechanisms 360used and on the contexts they are configured to determine, theprocessing unit 310 would be configured to perform conditional logicoperations and/or other operations to determine what is the primarydetected context upon which the decision to not transmit proximitywarnings, to transmit proximity warnings, or to transmit criticalproximity warnings should be based.

Notably, though the above description has been made with particularreferences to a collision avoidance system involving the use of devicesconfigured to form peer-to-peer networks, the devices in accordance withthe principles of the present invention will equally work with othercollision avoidance systems in which communication between the variousdevices is possible either directly or indirectly.

In use, the processing unit of vehicle device or of the personnel devicewill receive data from the context awareness mechanism(s) such as toreduce the transmission of non-hazardous proximity warnings when it isdetermined that the vehicle or person is in a non-hazardous situation,and to transmit critical proximity warnings when it is determined thatthe vehicle or person is in a highly hazardous or critical situation.However, if the processing unit determines that the context is neithernon-hazardous nor critical, it will cause the transmission of a regularproximity warning.

Understandably, by disabling the transmission of proximity warnings whena vehicle or a person is not in a location, position, state and/orstatus that pose a risk of collision, the devices in accordance with theprinciples of the present invention reduce the transmission ofnon-hazardous proximity warnings, thereby allowing vehicle operators andpersonnel to focus on hazardous proximity warnings. Also, bytransmitting critical proximity warnings when a vehicle or a person isin a highly hazardous or critical location, position, state and/orstatus, the devices in accordance with the principles of the presentinvention allow vehicle operators and personnel to become more awarewhen critical situations occur.

While illustrative and presently preferred embodiments of the inventionhave been described in detail hereinabove, it is to be understood thatthe inventive concepts may be otherwise variously embodied and employedand that the appended claims are intended to be construed to includesuch variations except insofar as limited by the prior art.

1) A collision avoidance device comprising: a) a processing unit; b) atransceiver comprising an antenna, the transceiver being incommunication with the processing unit and being capable of establishingwireless communications with other collision avoidance devices incommunication range to transmit and/or receive proximity warnings; c) auser interface in communication with the processing unit; d) at leastone context awareness mechanism in communication with the processingunit, the at least one context awareness mechanism being configured todetect a context in which the collision avoidance device is and totransmit data related to the detected context to the processing unit;wherein the processing unit is operable to 1) disable the transmissionof proximity warnings to at least some devices if the processing unitdetermines that the detected context is non-hazardous, 2) cause thetransmission of regular proximity warnings to at least some devices ifthe processing unit determines that the detected context is hazardous,or 3) cause the transmission of critical proximity warnings, differentfrom regular proximity warnings, to at least some devices if theprocessing unit determines that the detected context is criticallyhazardous. 2) The collision avoidance device as claimed in claim 1,wherein the device is configured to be mounted to a vehicle and whereinthe at least one context awareness mechanism comprises a vehicleinterface configured to determine at least one operating parameter ofthe vehicle. 3) The collision avoidance device as claimed in claim 2,wherein the at least one operating parameter of the vehicle comprisesthe ignition status, the oil pressure status, or the operating status ofthe lights of the vehicle. 4) The collision avoidance device as claimedin claim 1, wherein the device is configured to be mounted to a personand wherein the collision avoidance device is integrated into a cap lampcomprising a light operatively connected to a cap lamp controller. 5)The collision avoidance device as claimed in claim 4, wherein the atleast one context awareness mechanism comprises a cap lamp controllerinterface configured to detect an operating status of the light. 6) Thecollision avoidance device as claimed in claim 4, wherein the at leastone context awareness mechanism comprises a cap lamp charger interfaceconfigured to detect a charging status of the cap lamp. 7) A collisionavoidance system comprising a plurality of collision avoidance devicesmounted to vehicles and persons, the personnel collision avoidancedevices being configured to transmit proximity warnings to vehiclecollision avoidance devices in communication range, and the vehiclecollision avoidance devices being configured to transmit proximitywarnings to other vehicle collision avoidance devices and to personnelcollision avoidance devices in communication range; wherein each of thevehicle and personnel collision avoidance devices comprises at least onecontext awareness mechanism configured to detect a context in which thecollision avoidance device is; and wherein each of the vehicle andpersonnel collision avoidance devices is operable to 1) disable thetransmission of proximity warnings if the collision avoidance devicedetermines that the detected context is non-hazardous, 2) cause thetransmission of regular proximity warnings if the collision avoidancedevice determines that the detected context is hazardous, or 3) causethe transmission of critical proximity warnings, different from regularproximity warnings, if the collision avoidance device determines thatthe detected context is critically hazardous. 8) The collision avoidancesystem as claimed in claim 7, wherein the collision avoidance devicesfurther comprise obstacle collision avoidance devices, the obstaclecollision avoidance devices being configured to transmit proximitywarnings to vehicle collision avoidance devices in communication range.9) The collision avoidance system as claimed in claim 7, wherein the atleast one context awareness mechanism of the vehicle collision avoidancedevices comprises a vehicle interface configured to determine at leastone operating parameter of the vehicle. 10) The collision avoidancesystem as claimed in claim 9, wherein the at least one operatingparameter of the vehicle comprises the ignition status, the oil pressurestatus, or the operating status of the lights of the vehicle. 11) Thecollision avoidance system as claimed in claim 7, wherein the at leastone context awareness mechanism of the personnel collision avoidancedevices comprises a pressure sensor. 12) The collision avoidance systemas claimed in claim 11, wherein the pressure sensor is located in afootwear of the person. 13) The collision avoidance system as claimed inclaim 7, wherein the at least one context awareness mechanism of thepersonnel collision avoidance devices comprises a movement detector. 14)The collision avoidance system as claimed in claim 7, wherein thepersonnel collision avoidance devices are respectively integrated intocap lamps, each cap lamp comprising a light operatively connected to acap lamp controller. 15) The collision avoidance system as claimed inclaim 14, wherein the at least one context awareness mechanism of thepersonnel collision avoidance devices comprises a cap lamp controllerinterface configured to detect an operating status of the light. 16) Thecollision avoidance system as claimed in claim 14, wherein the at leastone context awareness mechanism of the personnel collision avoidancedevices comprises a cap lamp charger interface configured to detect acharging status of the cap lamp. 17) A method to control thetransmission of proximity warnings between collision avoidance devices,the collision avoidance devices comprising vehicle collision avoidancedevices, personnel collision avoidance devices, the personnel collisionavoidance devices being configured to transmit proximity warnings tovehicle collision avoidance devices in communication range, and thevehicle collision avoidance devices being configured to transmitproximity warnings to other vehicle collision avoidance devices and topersonnel collision avoidance devices in communication range, thevehicle and personnel collision avoidance devices each comprising atleast one context awareness mechanism, the method comprising, for eachof the vehicle and personnel collision avoidance devices: a) detecting,with the at least one context awareness mechanism, if the device is in anon-hazardous context, in a hazardous context, or in a criticallyhazardous context; b) as a function of the detected context, disablingthe transmission of proximity warnings if the detected context isnon-hazardous, transmitting proximity warnings if the detected contextis hazardous, or transmitting critical proximity warnings if thedetected context is critically hazardous. c) repeating steps a) and b).18) The method as claimed in claim 17, wherein the collision avoidancedevices further comprise obstacle collision avoidance devices, theobstacle collision avoidance devices being configured to transmitproximity warnings to vehicle collision avoidance devices incommunication range. 19) The method as claimed in claim 17, wherein thestep of detecting comprises, for vehicle collision avoidance devices,detecting an operating parameter of the vehicle. 20) The method asclaimed in claim 17, wherein the step of detecting comprises, forpersonnel collision avoidance devices, detecting a pressure generated bythe person, wherein the pressure is indicative of a sitting or standingposition of the person, and wherein a sitting-indicative pressure isindicative of a non-hazardous context, and wherein a standing-indicativepressure is indicative of a hazardous context. 21) The method as claimedin claim 20, wherein the pressure is detected in a footwear of thepersons. 22) The method as claimed in claim 17, wherein the personnelcollision avoidance devices are respectively integrated into cap lamps,each cap lamp comprising a light operatively connected to a cap lampcontroller. 23) The method as claimed in claim 22, wherein the step ofdetecting comprises, for personnel collision avoidance devices,detecting a cap lamp charging status, wherein a charging status isindicative of a non-hazardous context, and wherein a non-charging statusis indicative of a hazardous context. 24) The method as claimed in claim22, wherein the step of detecting comprises, for personnel collisionavoidance devices, detecting a cap lamp light operating status, whereina ON operating status is indicative of a hazardous context, and whereina OFF operating status is indicative of a critically non-hazardouscontext. 25) The method as claimed in claim 24, wherein the step ofdetecting further comprises, for personnel collision avoidance devices,detecting movements of the person, wherein detection of movements whilethe operating status of the cap lamp light is ON is indicative ofhazardous context, and wherein non-detection of movements for more thana predetermined period of time while the operating status of the caplamp light is ON is indicative of a critically hazardous context.